Process for obtaining fast dyeings and prints with vat dyestuffs



Patented Oct. 21, 1930 UNITED STATES.

PATENT-cri ics PHILIPPE BRANDT, 0F MULHOUSE, FRANCE, AND KARL GLENZ, OF BASED, SWITZER- LAND, ASSIGNORS TO THE FIRM DURAND &: HUGUENIN S. A., 01 BASED, SWITZER- LAND rnocass r03 OBTAINING FAST DYEINGS AND rmrrrs WITH var mmsrms Io Drawing. Application flled December 14, 1929, Serial No. 414,243, and in Germany December 22,1988.

ing and printing textile fibres and other materials (see U. S. Letters Patent No. 1,575,958).

This fundamental dyeing process has been modified in various directions (see U. S. Letters Patent No. 1,645,925 and U. S. patent application Ser. No. 202,473, filed June 29,

1927 Thus, the re-formation of the vat dyestulf on a fibre, "or in other words, the dyeing can be effected by means of an ester salt with a suitable oxidizing agent by a steaming operation in an analogous manner to what 1s the case with dyeings of aniline black.

This steam developing process, although modified and improved in different ways (see U. S. Patent No. 1,747,107 is'not yet quite satisfactory. What should be aimed at is a complete re-formation of the vat colour on the fibre, avoiding, however, any other disturbing reaction. This can only be attained if oxidizing agents, steam conditions, etc. are strictly adapted to the oxidizing condi tions required for the development of a spepossibility of application of the process is prejudiced.

It has now been found that this steam developing process for ester salts of leuco vat dyestuffs can be improved if certain mate rials are used which play the part of buffermaterials, i. e. which admit the oxidizin effect necessary for the development 0 the dyeing, but which render innoxious any possible excess of oxidizing agent.

Thus, it is possible to use a certain excess of oxidizingagent so that, on the one hand, in spite of bad steaming conditions which do not allow of a good use being made of the oxidizing agents, complete development can take place, and on the other hand, with good steaming conditions; an over-oxidation can be avoided.

Substances which meet the present case are aromatic amino-bodies containing a negative salt-forming group such as a sulphonic group or a carboxylic group. Such substances are therefore sulphonic acids or carboxylic acids respectively their salts of aniline, of the alkylanilines, of the homolo ues of these compounds, also of the napht yl-.

amines etc. These are bodies which are soluble in water, which are not volatile under con- N ditions of steaming and which under the pres-* ent circumstances do not form any disturbing oxidation colours.

In the present process the said products can either be added to the printing pastes or to the dr ester salts.

The e ect of the above mentioned additions could not be foreseen.

The process is explained by the following Print on cotton steam for 10 minutes in the rapid ager, soap for 1 minute at the boil, and wash. A well developed black dyeing is obtained. v

examples:

(I) Make up the following printing colour:

i Parts Ester salt of the leuco vat dyestufi 2- ,B-a-naphthindol-W-p-chloroanthra v cene-indigo containing 55% of vat dyestufl 7.2 Sodium'sulphanil-ate 4.2 Water 18 Diethyltartrate 8 Gum tragacanth thickening 50.6 Solution of sodium chlorate (10%) 12 Solution of vanadate of ammonia (1%) 4 Ammonia '1 If in this printing paste the sodium sulphanilate is omitted or is replaced by an indifi'erent substance, such as for instance, sodium sulphate, then, owing to overoxidation weak, dull, grey-green tints result.

(II) Make up the following printing colour:

Parts Ester salt of the leuco vat dyestufi' obtained from 5:.7-dibrom-isatin-achloride with a-anthol (see Colour Index No. 1203) containing 65% of vat dyestufl 3 Sodium salt of diethylaniline inetasulphonic acid 2 Water 922 Gum tragacanth thickening Solution of sodium chlorate (10%) 8 Solutiop of sulphocyanide of ammonia 1 I 1 4: Solution of vanadate of ammonia (1% l i 100 Print on cotton, steam tor l0 minutes in the rapid ager, soap and wash. Leveland well developed dyeings are obtained.

Without the addition of the sodium salt of diethylaniline meta-sulphonic acid, still useful, but bad, over-oxidized dyeings are obtained in accordance with the steaming con ditions.

III) Make up the following two printing colours a' and 5:

Parts Print on cotton, steam for 10 minutes, then soap and wash. In both-instances well developed reddish-blue tints are-obtained. If, however, the. sodium sulphanilate is omitted, or if this material is replaced by an indiflerent one, owing to over-oxidation only weak,

- greenish-blue tints are obtained.

When using the other indigosols according to the present process, advantageous results are also obtained.

In place of the additionsmentioned in the above examples, other substances, such as for instancemonoethyl-aniline-meta-or-para-sulphonic acid, monoor dimethyI-aniIine-metanr-para-sulphoriic acid, naphthylamine-suldyeing, this process being characterized by the fact that it is conducted in the presence 7 of an aromatic aminobody containing a negative salt-forming group.

2. A process for dyeing and printing with vat dyestufls by applying to the goods an ester salt of a leuco vat dyestutt, a suitable oxidizing agent and a substance capable of forming acid when heated, and engaging by steaming operation the acid oxidizing action necessary for the development of the dyeing, this process being characterized by the fact that it is conducted in the presence ofan aromatic aminobody with a negative salt-forming group, used in form of a salt.

3. A process for dyeing and printing with vat dyestufls by applying to the goods an ester salt of a leuco vat dyestufi', a suitable oxidizing agent and a substance capable of forming acid when heated, and engaging by a steamingoperation the acid 0x1 izlng action necessary for the development of the dyeing, this process bein characterized by the tact that it is conduct d in the presence,

of an aromatic amino sulpho body 4:. A process for dyeing and printing with vat dyestufis by applying to the goods an ester salt of a leuco vat dyestufi', a suitable oxidizing ageht and a substance capable ot ,tormlng acid when heated, and engaging by a steaming operation the acid oxidizing action necessary for the development of the dyeing, this process being characterized by the fact that it is conducted in the presence of an aromatic amino sulpho body used in form of a salt.

5. A process for dyeing and printing with vat dyestuffs by applying to the goods an ester salt of a leuco vat dyestuff, a suitable oxidizing agent and a substance capable of forming acid-when heated, and engaging by lis a steaming operation the acid oxidizlng action necessary for the development of the dyeing, this process being characterized by the fact that it is conducted in the presence of sodium sulphanilate.

In witness whereof we have hereunto this 3rd day of December,

PHILIPPE BRANDT. KARL GLENZ.

signed our name 1929. 

